DESCRIPTION: (Verbatim from the Applicant's Abstract) Partial seizures that originate from temporal or frontal neocortex often propagate extremely rapidly, representing some of the greatest challenges of seizure localization. Unfortunately experimental models using intact animals or in vitro systems have significant limitations on the study of factors influencing regional seizure spread. This project will use network models of reduced compartment neurons based on modified AvRon-Rinzel equations to investigate the characteristics and velocity of the patterns of propagating epileptiform activity. The influence of variables of connectivity, specifically the number and patterns of local connections will be studied in a network of neurons with net excitatory synaptic interactions. In addition, the influence of various intrinsic membrane properties on burst generation and seizure propagation will be studied. These model neurons will be assembled n various arrays of up to 62,500 connected neurons to study the influences of synaptic interactions on seizure propagation after burst generation. It is anticipated that these investigations will help explain the various specific characteristics that may contribute to the broad regional changes and extremely rapid propagation seen in seizures originating from the human neocortex, characteristics that distinguish neocortical onset seizures from other partial seizures (e.g. those originating from mesial temporal structures).